Switch devices for lead screw tapping units



Oct. 24, 1961 ZAGAR 3,005,884

SWITCH DEVICES FOR LEAD SCREW TAPPING UNITS Filed Sept. 23, 1959 Eigl. g 59 9 INVENTOR.

A's/15R 2/969? 52{ I 35 H TTOR'NE Y United State SWITCH DEVICES FOR LEAD SCREW TAPPING UNITS Asher I. Zagar, Brooklyn, N.Y., assignor to Ettco Tool & Machine Co., Inc., Brooklyn, N'.Y., a corporation of New York Filed Sept. 23, 1959, Ser. No. 841,843 Claims. (Cl. 200-47) This invention relates to tapping units and, more particularly, to the provision of adjustable switch devices controlling various drives of the lead screw in the operation of units of this type and kind.

Still more particularly, the invention deals with the provision of a switch actuating element having a ball bearing mounting on the lead screw with means retaining said element against rotation and for guiding the same in movement of the lead screw in both forward and reverse directions.

The novel features of the invention will be best understood from the following description, when taken together with the accompanying drawing, in which certain embodiments of the invention are disclosed and, in which, the separate parts are designated by suitable reference characters in each of the views and, in which:

FIG. 1 is a diagrammatic sectional view showing part of a tapping unit and a portion of the lead screw of the unit and illustrating one of my improved switch devices in elevation and also illustrating the switch actuating element in a position preparatory to actuating the switch device.

I FIG. 2 is a view looking generally in the direction of the arrow 2 of FIG. 1 of the switch device detached, with part of the construction broken away and in section.

FIG. 3 is a view looking in the direction of the arrow 3 of FIG. 2, with part of the construction broken away and in section; and

FIG. 4 is an enlarged partial section on the line 4-4 of FIG. 1, illustrating part of the switch in dot-dash lines.

In FIG. 1 of the drawing, 10, 10' illustrates part of theframe of a tapping unit. 11 illustrates part of the drive shaft operating in a bearing 12 of the frame 10' and extending into and adapted to actuate in the usual manner a lead screw 13. The lead screw is in threaded engagement with a bushing 14 supported in the frame 10 in controlling the forward and reverse drives of the lead screw. v

No other details of the tapping unit are deemed necessary to be illustrated, as these units are generally known in-the art and the unit is substantially of the type and kind disclosed in Patent Number 2,832,224, granted April 29, 1958.

With the present construction, the lead screw 13 is modified to the extent of providing thereon a reduced end 15, upon which a ball bearing 16 is mounted, the bearing being keyed in position by a suitable ring 17.

Supported on the bearing 16 is a switch actuating element 18 supporting a plain bearing 19, in which a guide and key rod 20 is arranged, the rod 20 being supported in the frames 10, 10', as clearly shown. In other words, in the forward and reverse feeds of the lead screw-13, the element 18 moves with the screw and along the rod 20 for'actuating switch devicescontrolling limit of forward and reverse travel and controlling reversing of the drive of the screw, as in other units of this type and kind.

It will-be understood that several switchllevices are employed but, as these devices would all be of the same general construction, the illustration of one is deemed to be sufficient.

Supported on the frame 10 and extending in the directionof the frame 10 are a pair of guide rods 21, be-

3,005,884 Patentedv Oct. 24:, .1961

switch devices, comprising a block 26 having apertures 27 therein, note FIG. 2, for reception of the rods 21. Intermediate the apertures 27 is a threaded bore 28, in which the screw 22 operates in adjusting the positioncf the switch actuating part or blade 29 with respect to the path of movement of the element 18. In this connection, it will be understood that the screw 22 is adjusted by a milled head 30 at one end thereof.

The blade 29 is supported on a lever 31 by a pair of screws 32, note FIG. 3 of the drawing. The lever is pivoted to the block 26 on a pin 33 screwed into the block, as indicated at 34, note FIG. 4. It will be noted that the block 26 has a threaded bore 26' opening throughboth surfaces of the block. The lever 31 is arranged between the pin head 35 and a spacing collar 36 disposed on the pin, as clearly noted in FIG. 4 of the drawing. It will thus be seen that the lever 31, or the upper end 37 thereof, is centrally disposed with respect to the actuating button 38 of a micro or other switch 39. The switch 39 is supported on the block 26 by a pair of bolts 40, as clearly noted in FIGS. 2 and 3 of the drawing.

It will be understood that the blade 29 has a degree of spring properties, so that, after the element 18 strikes the same to swing the lever 31 on its free pivot in actuating of the switch 39, by a slight depression of the button 38, the element 18 is free to move to a slight extent beyond the point of switch actuation, without in any way injuring the parts of the switch device as a whole. In the illustration of FIG. 1 of the drawing, the blade is actuated by the element 18 in movement of the lead screw 13 from right to left. In the reverse drive of the lead screw and after the element 18 has moved away from the blade 29, the blade will maintain its perpendicular position, as illustrated in FIG. 1 of the drawing, preparatory to receiving the next successive actuation by the element 18.

By adjustment of the switch device 25 through'the medium of the screw 22, the position of the blade 29-can be controlled for timely operation of the switch 39 in stopping movement of the lead screw in the one direction illustrated. As previously noted, at least one other switch device is employed in controlling the opposite movement of the lead screw. Such other device would have the switch arranged in the reverse direction, in other words, with the blade 29 at the right side, rather than at the left side, as noted in FIG. 1. of the drawing.

It will be understood that, by employing switch devices of the type and kind under consideration, substantially no wear factor will takevplace between the element 18 and the blade 29, in that the element 18 is non-rotatable and simply moves against and away from the blade 29, the lead screw 13 being freely rotatable in the element 18 by means of the ball bearing 16 which is provided.

By extending the threaded bore 26' through the block 26 and the apertures 27 and threaded aperture 28 also through the block, the switch device lends itself for different positionings of the parts, as will be apparent.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In lead screw tapping units employing a driven lead screw supported inthe frame of theunit, a switch device supported on the block and including a protruding switch button, a lever pivotally supported'on the block in alinement with said button, the lever including at one end an extended blade, the other end of the lever overlying said switch button, a switch actuating element supported on the lead screw and in which said lead screw is freely rotatable, means for keying and guiding said element in the frame in movement of the element with said lead screw in the forward and reverse movements of said lead screw, and said blade being disposed in the path of movement of said element for actuation by the element in depressing said button by the second named end of said lever.

2. In lead screw tapping units employing a driven lead screw supported in the frame of the unit, a switch device controlling movement of the lead screw in at least one direction, said device comprising a block, a screw supported in the frame for adjusting the position of said block longitudnally with respect to said lead screw, means for keying the block against rotation in the frame, a switch supported on the block and including a protruding switch button, a lever pivotally supported on the block in alinement with said button, the lever including at one end an extended blade, the other end of the lever overlying said switch button, a switch actuating element supported on the lead screw and in which said lead screw is freely rotatable, means for keying and guiding said element in the frame in movement of the element with said lead screw in the forward and reverse movements of said lead screw, said blade being disposed in the path of movement of said element for actuation by the second named end of the element in depressing said button by said lever, and said first named means comprising a pair of guide rods supported in the frame and on which said block is slidably mounted.

3. In lead screw tapping units employing a driven lead screw supported in the frame of the unit, a switch device controlling movement of the lead screw in at least one direction, said device comprising a block, a screw supported in the frame for adjusting the position of said block longitudinally with respect to said lead screw, means for keying the block against rotation in the frame, a switch supported on the block and including a protruding switch button, a lever pivotally supported on the block in alinement with said button, the lever including at one end an extended blade, the other end of the lever overlying said switch button, a switch actuating element supported on the lead screw and in which said lead screw is freely rotatable, means for keying and guiding said element in the frame in movement of the element with said lead screw in the forward and reverse movements of said lead screw, said blade being disposed in the path of movement of said element for actuation by the element in depressing said button by the second named end of said lever, and said second named means comprising a rod supported in the frame and on which said element is longitudinally movable.

4. In lead screw tapping units employing a driven lead screw supported in theframe of the unit, a switch device controlling movement of the lead screw in at least one direction, said device comprising a block, a screw supported in the frame for adjusting the position of said block longitudinally with respect to said lead screw, means for keying the block against rotation in the frame, a switch supported on the block and including a protruding switch button, a lever pivotally supported on the block in alinement with said button, the lever including at one end an extended blade, the other end of the lever overlying said switch button, a switch actuating element supported on the lead screw and in which said lead screw is freely rotatable, means for keying and guiding said element in the frame in movement of the element with said lead screw in the forward and reverse movements of said lead screw, said blade being disposed in the path of movement of said element for actuation by the element in depressing said button by the second named end of said lever, and

said lead screw having a ball bearing mounting in said element for free rotation therein.

5. In lead screw tapping units employing a driven lead screw supported in the frame of the unit, a switch device controlling movement of the lead screw in at least one direction, said device comprising a block, a screw supported in the frame for adjusting the position of said block longitudinally with respect to said lead screw, means for keying the block against rotation in the frame, a switch supported on the block and including a protruding switch button, a lever pivotally supported on the block in alinement with said button, the lever including at one end an extended blade, the other end of the lever overlying said switch button, a switch actuating element supported on the lead screw and in which said lead screw is freely rotatable, means for keying and guiding said element in the frame in movement of the element with said lead screw in the forward and reverse movements of said lead screw, said blade .being disposed in the path of movement of said element for actuation by the element in depressing said button by the second named end of said lever, and said blade having spring properties.

6. In lead screw tapping units of the character described emplo n'ng a forward and reverse driven lead screw, a switch device supported adjacent and adjustable longitudinally of the axis of the lead screw, an actuating element movable with said lead screw, means for keying said element against rotation with the screw, said switch device including a switch actuating part arranged in the path of movement of said element and actuated by said element in checking movement of the lead screw in one direction, and means for keying and guiding the switch device in its adjustable movement.

7. In lead screw tapping units of the character described employing a forward and reverse driven lead screw, a switch device supported adjacent and adjustable longitudinally of the axis of the lead screw, an actuating element movable with said lead screw, means for keying said element against rotation with the screw, said switch device including a switch actuating part arranged inthe path of movement of said element and actuated by-s-aid element in checking movement of the lead screw in one direction, means for keying and guiding the switch device in its adjustable movement, and said switch actuating part including a freely rotatable lever having opposed ends, one end of the lever being arranged in alinement with a button of said switch for direct operation of the button when the other end of said lever is actuated by said element.

8. A switch device comprising a block having a pair of parallel apertures therein, a threaded bore arranged intermediate and paralleling said apertures, a switch supported at one side portion of the block and on one surface thereof, the block having a threaded aperture opening through both side surfaces of the block, a'pivot pin supported in said last named threaded aperture and project ing on the surface of the block, upon which the switch is mounted, a lever freely rotatable on said pin, said lever having an end arranged in alinement with and adapted to actuate a button of said switch, and the other end ofsaid lever including an extended part adapted to be positioned in the path of movement of a switch actuating element, whereby movement of said part Will actuate said lever to depress said button.

9. A switch device comprising a block having a pair of parallel apertures therein, a threaded bore arranged intermediate and paralleling said apertures, a switch supported at one side portion of the block and on one surface thereof, the block having a threaded aperture opening through both side surfaces of the block, a pivot pin supported in said last named threaded aperture and projecting on the surface of the block, upon which the switch is mounted, a lever freely rotatable on said pin, said lever having an end arranged in alinement with and adapted to actuate a button of said switch, the other endof said lever including an extended part adapted to be positioned in the path of movement of a switch actuating element, whereby movement of said part will actuate said lever to depress said button, a switch adjusting screw in threaded engagement with the first named threaded aperture of said block, and a pair of guide rods supported in said pair of apertures for guiding the block in adjustment thereof by said screw to control positioning of said part with respect to path of movement of said element.

10. A switch device comprising a block having a pair of parallel apertures therein, a threaded bore arranged intermediate and paralleling said apertures, a switch supported at one side portion of the block and on one surface thereof, the block having a threaded aperture opening through both side surfaces of the block, a pivot pinsupported in said last named threaded aperture and projecting on the surface of the block, upon which the switch is mounted, a lever freely rotatable on said pin, said lever having an end arranged in alinement with and adapted to actuate a button of said switch, the other end of said lever including an extended part adapted to be positioned in the path of movement of a switch actuating element, whereby movement of said part will actuate said lever to depress said button, a switch adjusting screw in threaded engagement with the first named threaded aperture of said block, a pair of guide rods supported in said pair of apertures for guiding the block in adjustment thereof by said screw to control positioning of said part with respect to path of movement of said element, and said part having spring properties.

References Cited in the file of this patent UNITED STATES PATENTS 

